Vltor Weapon Systems blew a lot of people away with their new VIS-1 one-piece upper receiver/rail system (upper receiver with integral rail). Actually, the Vltor VIS-1 is constructed of two pieces that are bonded together in such a way that it’s virtually seamless and super-strong. No doubt, the VIS-1 will be going up against the Lewis Machine & Tool (LMT) Monolithic Rail Platform (MRP). The difference? The LMT MRP utilizes a proprietary barrel and gas tube assembly for it’s QCBS (Quick Change Barrel System), while the Vltor VIS-1 utilizes commercial off-the-shelf (COTS) AR-15/M16/M4 barrels and gas tubes. According to Vltor, the VIS-1’s quick change barrel system is similar in speed to accomplish as the LMT MRP.

The VIS-1 is a hot system, and anyone looking for a “monolithic”-type setup should definitely give it serious consideration, along with the LMT MRP, which is also excellent. By the way, the “VIS” in “VIS-1” stands for two things: 1) Versatile Interface Structure, and 2) In Latin, VIS means “force” or “to use force”. While we’re on the subject of Latin, Vltor (pronounced “Ooltor”) means “revenge”, “avenger” or “vengeance”. The “1” designation in “VIS-1” is for Vltor’s carbine series. Vltor’s mid-length series will be called VIS-2, and their rifle-length series will be designated “VIS-3”. The process Vltor uses for bonding the two pieces of the upper receiver into one piece is salt dip brazing, which utilizes a molten salt vat. According to Eric Kincel, salt dip brazing is a dying art form. It creates a one-piece unit that has the same strength and rigidity as solid piece of aluminum. The mating joint (bonded surfaces) are actually stronger than the parent metal (parent material).
Other than the Vltor VIS upper receiver/rail platform, the most interesting aspect of the weapon is it’s 6.5mm caliber. The weapon utilizes the 6.5 Grendel cartridge developed by Bill Alexander of Alexander Arms, which would appear to be the most versatile domestically-developed modern combat caliber that DefenseReview has seen. In fact, if we had to choose one cartridge to take into battle with us and handle all likely combat shooting tasks from CQB/CQC to long-range sniping, we’d probably choose the 6.5 Grendel, provided we didn’t have to worry about ammo availability and component/parts replacement issues for our weapons. Where the 6.8x43mm SPC (a.k.a. 6.8mm SPC a.k.a. 6.8 SPC) cartridge starts losing steam and effectiveness after approximately 500-600 yards, the 6.5 Grendel can reach out and smack you effectively at long range out to 1000-1200 yards. At CQB/CQC-to-medium range, the 6.5 Grendel and 6.8 SPC seem to offer similar terminal ballistics. We’ll let the ballisticians argue over which is superior at realistic infantry combat ranges/distances out to 300 yards, but both cartridges offer significantly greater terminal ballistics over the 5.56x45mm NATO (5.56mm NATO)/.223 Rem. cartridge.

The article includes a 6.8 SPC vs. 6.5 Grendel velocity comparison chart which compares respective velocities at various ranges:

Load (gr) Muzzle (fps) 100m 300m 500m 800m 1000m

6.8 SPC 115 2700 2417 1903 1470 1055 929

6.5 Grendel 123 2600 2426 2098 1797 1410 1211

The 6.5mm Grendel sounds pretty great, doesn’t it? Well, it is pretty great. So, what’s the catch? The catch is that the Grendel is a wildcat cartridge and there are currently only three companies that manufacture it, according to Cutshaw. They are Alexander Arms, Black Hills Ammunition, and Wolf Performance Ammunition. Black Hills is of course famous for manufacturing the excellent and combat-proven Mk 262 Mod 1 (also written MK262 MOD1) 5.56mm round, which utilizes a which utilizes 77-grain (77gr) Sierra MatchKing OTM (Open-Tip Match) bullet, first utilized by military operators running the Mk 12 Mod 0/1 SPR (also written Mk12 Mod0/1 SPR) to hit bad guys out to approx. 600 yards.

The Black Hills 6.5 Grendel round utilizes a 123-grain (123gr) Sierra MatchKing bullet. The Alexander Arms round utilizes a 123gr Lapua Scenar HPBT (Hollow Point Boattail) bullet that remains supersonic beyond 1000 yards due to its impressive 0.547 BC (Ballistic Coefficient). In the SWMP piece, Cutshaw states that additional 6.5 Grendel loads are currently in development and should be available soon, including a 90gr Speer TNT (BC 0.281), 120gr Nosler (BC 0.458), and 129gr Hornady SST (BC 0.485).

The Vltor/POF-USA 6.5 Grendel SPR-type carbine/rifle shot 0.5 MOA (Minute-Of-Angle) groups. The best 3-shot group was a rather astonishing 0.25 inches. The two-stage POF match trigger broke at 3.5 pounds (3.5 lbs). Cutshaw experienced zero stoppages, and claims that felt recoil was “about the same as a .223, although I didn’t do a side-by-side comparison.”

The Vltor VIS-2 upper receiver’s unique tactical bipod no doubt assisted Mr. Cutshaw in achieving the above multiple-shot groups. The Vltor tactical bipod mounts on top of the VIS’ free-float handguard/rail system rather than below it like conventional bipods do. A top-mounted bipod lowers the rifle’s center of gravity by approximately 2 inches, “making it much more stable and less prone to being knocked over when someone accidentally bumps against it with their foot,” Cutshaw writes. He adds “Vltor’s bipod doesn’t absolutely prevent the rifle from being knocked over, but it significantly reduces the chances of that happening.”

Cutshaw also mentioned Vltor’s proprietary flash suppressor/muzzle brake and fully-adjustable BUIS (Back Up Iron Sight) system (front and rear) “that lock firmly into place when up and rise easily with the touch of a finger.”

About David Crane

David Crane started publishing online in 2001. Since that time, governments, military organizations, Special Operators (i.e. professional trigger pullers), agencies, and civilian tactical shooters the world over have come to depend on Defense Review as the authoritative source of news and information on "the latest and greatest" in the field of military defense and tactical technology and hardware, including tactical firearms, ammunition, equipment, gear, and training.